The present invention relates to an impact resistant and heat aging resistant polyphenylene ether resin composition excellent in flame retardancy.
2. Description of the Prior Art
Since polyphenylene ether resins provide moldings excellent in heat resistance and rigidity, the application thereof as an engineering plastic is increasing, and attempts to enhance its performance are being made. For example, as a method of improving the impact resistance of moldings of polyphenylene ether resins, blending of polybutadiene elastomers is disclosed in Japanese Patent Publication No. 32731/1972. However, in such a method, since unsaturated bonds remain in the polybutadiene elastomer, the blended resin thus obtained is thermally unstable and the resin is not excellent in heat aging resistance.
When the application to electric parts that are increasing in recent years is considered, in addition to heat aging resistance, flame retardancy and impact resistance are required to be improved.
It is disclosed in Laid Open Japanese Patent Application 69859/1988 that when a modified polyorganosiloxane polymer was used as a source of an impact resistant rubber, a resin having an excellent impact resistance, heat resistance and mechanical strength could be acquired. Further, Japanese Patent Publication No. 418/1978 discloses the addition of a phosphate to a polyphenylene ether resin to improve the flame retardancy of the resin.
However, even if a phosphate is added to the polyphenylene ether resin blended with a modified polyorganosiloxane polymer, satisfactory flame retardancy of the blend was not secured actually.